git.sur5r.net Git - u-boot/blob - drivers/ps2ser.c

   1 /***********************************************************************
   2  *
   3  * (C) Copyright 2004
   4  * DENX Software Engineering
   5  * Wolfgang Denk, wd@denx.de
   6  * All rights reserved.
   7  *
   8  * Simple 16550A serial driver
   9  *
  10  * Originally from linux source (drivers/char/ps2ser.c)
  11  *
  12  * Used by the PS/2 multiplexer driver (ps2mult.c)
  13  *
  14  ***********************************************************************/
  15
  16 #include <common.h>
  17
  18 #ifdef CONFIG_PS2SERIAL
  19
  20 #include <asm/io.h>
  21 #include <asm/atomic.h>
  22 #include <ps2mult.h>
  23
  24 /* #define      DEBUG */
  25
  26 #define PS2SER_BAUD     57600
  27
  28 static int      ps2ser_getc_hw(void);
  29 static void     ps2ser_interrupt(void *dev_id);
  30
  31 extern struct   serial_state rs_table[]; /* in serial.c */
  32 static struct   serial_state *state;
  33
  34 static u_char   ps2buf[PS2BUF_SIZE];
  35 static atomic_t ps2buf_cnt;
  36 static int      ps2buf_in_idx;
  37 static int      ps2buf_out_idx;
  38
  39
  40 static inline unsigned int ps2ser_in(int offset)
  41 {
  42         return readb((unsigned long) state->iomem_base + offset);
  43 }
  44
  45 static inline void ps2ser_out(int offset, int value)
  46 {
  47         writeb(value, (unsigned long) state->iomem_base + offset);
  48 }
  49
  50 int ps2ser_init(void)
  51 {
  52         int quot;
  53         unsigned cval;
  54
  55         state = rs_table + CONFIG_PS2SERIAL;
  56
  57         quot = state->baud_base / PS2SER_BAUD;
  58         cval = 0x3; /* 8N1 - 8 data bits, no parity bits, 1 stop bit */
  59
  60           /* Set speed, enable interrupts, enable FIFO
  61            */
  62         ps2ser_out(UART_LCR, cval | UART_LCR_DLAB);
  63         ps2ser_out(UART_DLL, quot & 0xff);
  64         ps2ser_out(UART_DLM, quot >> 8);
  65         ps2ser_out(UART_LCR, cval);
  66         ps2ser_out(UART_IER, UART_IER_RDI);
  67         ps2ser_out(UART_MCR, UART_MCR_OUT2 | UART_MCR_DTR | UART_MCR_RTS);
  68         ps2ser_out(UART_FCR,
  69             UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
  70
  71         /* If we read 0xff from the LSR, there is no UART here
  72          */
  73         if (ps2ser_in(UART_LSR) == 0xff) {
  74                 printf ("ps2ser.c: no UART found\n");
  75                 return -1;
  76         }
  77
  78         irq_install_handler(state->irq, ps2ser_interrupt, NULL);
  79
  80         return 0;
  81 }
  82
  83 void ps2ser_putc(int chr)
  84 {
  85 #ifdef DEBUG
  86         printf(">>>> 0x%02x\n", chr);
  87 #endif
  88
  89         while (!(ps2ser_in(UART_LSR) & UART_LSR_THRE));
  90
  91         ps2ser_out(UART_TX, chr);
  92 }
  93
  94 static int ps2ser_getc_hw(void)
  95 {
  96         int res = -1;
  97
  98         if (ps2ser_in(UART_LSR) & UART_LSR_DR) {
  99                 res = (ps2ser_in(UART_RX));
 100         }
 101
 102         return res;
 103 }
 104
 105 int ps2ser_getc(void)
 106 {
 107         volatile int chr;
 108         int flags;
 109
 110 #ifdef DEBUG
 111         printf("<< ");
 112 #endif
 113
 114         flags = disable_interrupts();
 115
 116         do {
 117                 if (atomic_read(&ps2buf_cnt) != 0) {
 118                         chr = ps2buf[ps2buf_out_idx++];
 119                         ps2buf_out_idx &= (PS2BUF_SIZE - 1);
 120                         atomic_dec(&ps2buf_cnt);
 121                 } else {
 122                         chr = ps2ser_getc_hw();
 123                 }
 124         }
 125         while (chr < 0);
 126
 127         if (flags) enable_interrupts();
 128
 129 #ifdef DEBUG
 130         printf("0x%02x\n", chr);
 131 #endif
 132
 133         return chr;
 134 }
 135
 136 int ps2ser_check(void)
 137 {
 138         int flags;
 139
 140         flags = disable_interrupts();
 141         ps2ser_interrupt(NULL);
 142         if (flags) enable_interrupts();
 143
 144         return atomic_read(&ps2buf_cnt);
 145 }
 146
 147 static void ps2ser_interrupt(void *dev_id)
 148 {
 149         int chr;
 150         int iir;
 151
 152         do {
 153                 chr = ps2ser_getc_hw();
 154                 iir = ps2ser_in(UART_IIR);
 155                 if (chr < 0) continue;
 156
 157                 if (atomic_read(&ps2buf_cnt) < PS2BUF_SIZE) {
 158                         ps2buf[ps2buf_in_idx++] = chr;
 159                         ps2buf_in_idx &= (PS2BUF_SIZE - 1);
 160                         atomic_inc(&ps2buf_cnt);
 161                 } else {
 162                         printf ("ps2ser.c: buffer overflow\n");
 163                 }
 164         } while (iir & UART_IIR_RDI);
 165
 166         if (atomic_read(&ps2buf_cnt)) {
 167                 ps2mult_callback(atomic_read(&ps2buf_cnt));
 168         }
 169 }
 170
 171 #endif /* CONFIG_PS2SERIAL */